5.3 or LS6 style Heads

**ksupersport02** · 01-08-2008, 09:49 AM

Hey,

To all that know their stuff. I am fixing to buy a head cam package. What are the 5.3 heads that i keep seeing. Are these not truck heads. And if so, why would you want to use these smaller heads vs a 5.7 ls6 head. I am fixing to buy and dont want to sound stupid when i place my order. Also what difference is there between the ported, stage 2 and stage 3 heads. I want a very thumpy cam, looking at the MS4, due to the fact that car is not daily driver. Any way, i have seen thousands of threads on here about these topics, but no one really answers them.. Hopefully, all of the tech gods will read this.

Any help is greatly appreciated.

KD

**WARP211** · 01-08-2008, 10:40 AM

5.3L heads are truck heads. and from my understanding they have better flowing and port capabiltes on them than the 5.7L Bascially the 5.3L are better for porting than the 5.7L head. check out TEA 5.3L vs 5.7l vs LS-6 heads.. check out their web site.

http://www.totalengineairflow.com

**INMY01TA** · 01-08-2008, 09:59 PM

5.3 heads raise the compression and work well on a 346. Hate to redirect you to another site but read some good threads lately on this.
http://www.ls1tech.com/forums/showthread.php?t=839480
http://www.ls1tech.com/forums/showthread.php?t=819108

**ksupersport02** · 01-09-2008, 02:13 AM

Ok, Those are great articles . They help clear up alot.
One more question. Will the MS4 or other big thumpy cams work good with these or should i just get the patriot LS6 heads.

Thanks

**ksupersport02** · 01-09-2008, 03:52 AM

Hey also cant seem to find any information referring to diff between Stage 1, 2 , 3 heads. Are the flow numbers diff or hp gains.

**0rion** · 01-09-2008, 03:56 AM

stage number reflects the amount of work done to the heads such as port, polish, larger valves, and things like that. The higher the number the more the heads have been worked.

**SSwt00SS** · 01-09-2008, 05:38 AM

I have Ls6 Style Stage II heads from Patriot Performance. The are the old 6.0L truck castings welded up to 59cc chambers (2.02"int/1.57"ext). they happened to increase my C/R to about 11.5:1.

the difference between stage II and III heads from Patriot are that the stage III are made for larger displacement engine like a 383, 402, 408, etc. the stage II heads are perfect for any stock or close to stock bore engines.

what you need to have in mind is the size of the 'CC' chambers as you will need to make sure that you wont have piston to valve clearance issues. the smaller the 'cc' chambers the chances that you will run into this problem increase. if that is the case you will have to flycut your pistons to get the proper clearance.

my setup is a little 224 cam and the Patriot stage II heads. with that setup I am putting down 437/404 to the wheels. i also know for a fact that with this set up i am putting down more power (HP/TQ) than a fellow member who has 5.3 heads (1.5 stage) and an MS4. both our cars are m6...

my dyno sheet from Dec 2007 (yes i know the year is wrong on the sheet)...my old numbers were 444/395 before simply swapping from a catback to TSP TD's (no retune)...

old dyno sheet from August 2007...SLP LM catback

**ksupersport02** · 01-09-2008, 11:35 AM

Ok thanks, thats the best explanation i have heard
So what CC should i get to avoid clearance problems. I have seen the 64cc. Will these be a problem with the MS4 cam. I obviously have a stock 346. headers will be changed at the same time, Hopefully the group purchase will come through...

**INMY01TA** · 01-10-2008, 06:08 PM

Originally Posted by ksupersport02

Ok thanks, thats the best explanation i have heard
So what CC should i get to avoid clearance problems. I have seen the 64cc. Will these be a problem with the MS4 cam. I obviously have a stock 346. headers will be changed at the same time, Hopefully the group purchase will come through...

If your dead set on the MS4 I'd call Texas Speed and have them pick the best LS6 heads for your 346.

**maxpit** · 01-11-2008, 06:39 AM

LS6 heads r the way to go. Awell ported ported LS6(not even talking about race porting) will perform just as good as a set of AFR's.

**SSwt00SS** · 01-11-2008, 07:03 AM

i love my patriot heads. i got them brand new for $900 off a member of this site. compared to the price of AFR's i couldnt justify spending $1000+ for only 5-7rwhp difference...

im not saying AFR's arent good, but out of my price range and sometimes the price range of many...

personally i would go Ls6 heads and have them milled down to increase your C/R. then find a good cam or even a custom grind cam that will work with your setup without having to flycut your pistons...

**Marc 85Z28** · 01-12-2008, 09:19 AM

I'm running Texas Speed PRC stage 2.5 5.3L heads and the MS4 cam. They work EXTREMELY well together, and made significant more power than my old very expensive "best money can buy" setup from years ago. THe 5.3L truck heads give a higher compression ratio, which the bigger cams absolutely love. However I don't believe you can run this combo without cutting the pistons. The PRC stage 1 LS6 heads would clear, but you're leaving a lot of power on the table with that combo. My car runs high 10s on stock shortblock naturally aspirated. Sounds good too: http://s165.photobucket.com/albums/u...95_toMPEG1.flv

**Wheeler99WS6** · 01-13-2008, 09:12 AM

I havent done heads and cam just yet so I am not sure but I always heard that if you were going with FI then get the 5.3L heads but if going NA then get the LS6 heads.

**Marc 85Z28** · 01-13-2008, 04:46 PM

Originally Posted by Wheeler99WS6

I havent done heads and cam just yet so I am not sure but I always heard that if you were going with FI then get the 5.3L heads but if going NA then get the LS6 heads.

No no no. 5.3L heads are better suited for an NA application due to the increase in compression ratio. An LS6 would work, but again they increase compression ratio as well. For a boosted engine lower compression is better. So a 6.0L is more ideally suited, and that's what most guys use

**ksupersport02** · 01-14-2008, 02:47 AM

Originally Posted by Marc 85Z28

I'm running Texas Speed PRC stage 2.5 5.3L heads and the MS4 cam. They work EXTREMELY well together, and made significant more power than my old very expensive "best money can buy" setup from years ago. THe 5.3L truck heads give a higher compression ratio, which the bigger cams absolutely love. However I don't believe you can run this combo without cutting the pistons. The PRC stage 1 LS6 heads would clear, but you're leaving a lot of power on the table with that combo. My car runs high 10s on stock shortblock naturally aspirated. Sounds good too: http://s165.photobucket.com/albums/u...95_toMPEG1.flv

Car does sound good , thats exactly what i was looking for. However, did you have to flycut your pistons or did you have a shop do the work. A buddy and i will be installing these. Should i just ask the guys at TS. I have emailed them several times about packages, but dont ever get a response.

**Marc 85Z28** · 01-14-2008, 03:04 AM

With my particular setup I did have to cut the pistons. But that's due to the fact that I had the heads milled down to 59cc, ran a thinner than stock head gasket at .040", and had the cam ground on a different LSA than standard. Other than the tune, all work was done by me.

**ksupersport02** · 01-14-2008, 03:10 AM

awsome.. i figured you had them milled or something. That means i will prob be alright as long as i run 64cc or so. You said you have the MS4.. what LSA did you get?

**Marc 85Z28** · 01-14-2008, 05:06 AM

Originally Posted by ksupersport02

awsome.. i figured you had them milled or something. That means i will prob be alright as long as i run 64cc or so. You said you have the MS4.. what LSA did you get?

110 LSA. GMHighTechPerformance did a PRC stage 1 LS6 and MS4 cam buildup last year. They did NOT cut the pistons, and had outstanding results. I believe they sink the valves into the head a little on the LS6 stuff for PTV clearance. Detailed buildup with all power figures can be found here: http://www.gmhightechperformance.com...ech/index.html

**ksupersport02** · 01-14-2008, 05:48 AM

Ok nice. Did TSP give you everything you needed in a package.. Or did you have to piece mill.. Also ball park,, not being nosy,, how bad did they set you back?

**Wheeler99WS6** · 01-14-2008, 06:36 AM

Originally Posted by Marc 85Z28

No no no. 5.3L heads are better suited for an NA application due to the increase in compression ratio. An LS6 would work, but again they increase compression ratio as well. For a boosted engine lower compression is better. So a 6.0L is more ideally suited, and that's what most guys use

You know what that does sound right. Thanks for clearing up my mispost though. I hate to steer some one in the wrong direction.